Plant growth and flowering in the Arctic System Science Program (ARCSS) grid at Utqiaġvik and Atqasuk, Alaska

Arctic ecosystems are changing in response to arctic warming, which is proceeding more than twice as fast as the global average. The International Tundra Experiment (ITEX) was established in the early 1990s to understand the effects of warming and environmental variability on tundra vegetation properties and ecosystem function. The ITEX program has been extremely valuable for detection of changes in tundra plant and ecosystem responses to experimental warming and to background climate change across sites that span the major ecosystems of the Arctic. These files contain data representing the periodic plant measures of species within each plot in a comma delimited format. The data presented are seasonal growth of graminoids (length of leaf, and length of inflorescence) and seasonal flowering of all species (number of inflorescences in flower within a plot), collected weekly during the summers of 2012-2019 for a subset of 30 grid plots at two sites (Utqiaġvik, formerly Barrow, Arctic System Science Program (ARCSS) grid and Atqasuk ARCSS grid) and during the summer of 2021 for a subset of 30 grid plots at one site (Utqiaġvik ARCSS grid).